Advocacy group Common Cause said Monday it had filed an IRS complaint accusing ALEC of masquerading as a public charity. ALEC is formed as a nonprofit that brings together lawmakers and private sector organizations to develop legislation and policy.

ALEC has said its work is not lobbying, but Common Cause disagrees.

Several companies who have previously supported ALEC financially have dropped out in recent weeks amid backlash tied to the group's support of "Stand Your Ground" laws, such as the one cited as a defense in the shooting of Florida teenager Trayvon Martin.